#include <typeinfo>
#include <utility>
#include <assert.h>
#include <iostream>
#include <vector>
#include <string>
#include <cassert>
#include <cstring>
#include <ctime>
#include <functional>
#include <unordered_map>
#include <thread>
#include <mutex>
#include <condition_variable>
#include <memory>
#include <typeinfo>
#include <fcntl.h>
#include <signal.h>
#include <unistd.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <sys/epoll.h>
#include <sys/eventfd.h>
#include <sys/timerfd.h>

#define INF 0
#define DBG 1
#define ERR 2
#define LOG_LEVEL DBG

#define LOG(level, format, ...)                                                                                        \
    do                                                                                                                 \
    {                                                                                                                  \
        if (level < LOG_LEVEL)                                                                                         \
            break;                                                                                                     \
        time_t t = time(NULL);                                                                                         \
        struct tm *ltm = localtime(&t);                                                                                \
        char tmp[32] = {0};                                                                                            \
        strftime(tmp, 31, "%H:%M:%S", ltm);                                                                            \
        fprintf(stdout, "[%p %s %s:%d] " format "\n", (void *)pthread_self(), tmp, __FILE__, __LINE__, ##__VA_ARGS__); \
    } while (0)

#define INF_LOG(format, ...) LOG(INF, format, ##__VA_ARGS__)
#define DBG_LOG(format, ...) LOG(DBG, format, ##__VA_ARGS__)
#define ERR_LOG(format, ...) LOG(ERR, format, ##__VA_ARGS__)

#define BUFFER_DEFAULT_SIZE 1024
class Buffer
{
private:
    std::vector<char> _buffer; // 使用vector进行内存空间管理
    uint64_t _reader_idx;      // 读偏移
    uint64_t _writer_idx;      // 写偏移
public:
    Buffer() : _reader_idx(0), _writer_idx(0), _buffer(BUFFER_DEFAULT_SIZE) {}
    char *Begin() { return &*_buffer.begin(); }
    // 获取当前写入起始地址, _buffer的空间起始地址，加上写偏移量
    char *WritePosition() { return Begin() + _writer_idx; }
    // 获取当前读取起始地址
    char *ReadPosition() { return Begin() + _reader_idx; }
    // 获取缓冲区末尾空闲空间大小--写偏移之后的空闲空间, 总体空间大小减去写偏移
    uint64_t TailIdleSize() { return _buffer.size() - _writer_idx; }
    // 获取缓冲区起始空闲空间大小--读偏移之前的空闲空间
    uint64_t HeadIdleSize() { return _reader_idx; }
    // 获取可读数据大小 = 写偏移 - 读偏移
    uint64_t ReadAbleSize() { return _writer_idx - _reader_idx; }
    // 将读偏移向后移动
    void MoveReadOffset(uint64_t len)
    {
        if (len == 0)
            return;
        // 向后移动的大小，必须小于可读数据大小
        assert(len <= ReadAbleSize());
        _reader_idx += len;
    }
    // 将写偏移向后移动
    void MoveWriteOffset(uint64_t len)
    {
        // 向后移动的大小，必须小于当前后边的空闲空间大小
        assert(len <= TailIdleSize());
        _writer_idx += len;
    }
    // 确保可写空间足够（整体空闲空间够了就移动数据，否则就扩容）
    void EnsureWriteSpace(uint64_t len)
    {
        // 如果末尾空闲空间大小足够，直接返回
        if (TailIdleSize() >= len)
        {
            return;
        }
        // 末尾空闲空间不够，则判断加上起始位置的空闲空间大小是否足够, 够了就将数据移动到起始位置
        if (len <= TailIdleSize() + HeadIdleSize())
        {
            // 将数据移动到起始位置
            uint64_t rsz = ReadAbleSize();                            // 把当前数据大小先保存起来
            std::copy(ReadPosition(), ReadPosition() + rsz, Begin()); // 把可读数据拷贝到起始位置
            _reader_idx = 0;                                          // 将读偏移归0
            _writer_idx = rsz;                                        // 将写位置置为可读数据大小， 因为当前的可读数据大小就是写偏移量
        }
        else
        {
            // 总体空间不够，则需要扩容，不移动数据，直接给写偏移之后扩容足够空间即可
            DBG_LOG("RESIZE %ld", _writer_idx + len);
            _buffer.resize(_writer_idx + len);
        }
    }
    // 写入数据
    void Write(const void *data, uint64_t len)
    {
        // 1. 保证有足够空间，2. 拷贝数据进去
        if (len == 0)
            return;
        EnsureWriteSpace(len);
        const char *d = (const char *)data;
        std::copy(d, d + len, WritePosition());
    }
    void WriteAndPush(const void *data, uint64_t len)
    {
        Write(data, len);
        MoveWriteOffset(len);
    }
    void WriteString(const std::string &data)
    {
        return Write(data.c_str(), data.size());
    }
    void WriteStringAndPush(const std::string &data)
    {
        WriteString(data);
        MoveWriteOffset(data.size());
    }
    void WriteBuffer(Buffer &data)
    {
        return Write(data.ReadPosition(), data.ReadAbleSize());
    }
    void WriteBufferAndPush(Buffer &data)
    {
        WriteBuffer(data);
        MoveWriteOffset(data.ReadAbleSize());
    }
    // 读取数据
    void Read(void *buf, uint64_t len)
    {
        // 要求要获取的数据大小必须小于可读数据大小
        assert(len <= ReadAbleSize());
        std::copy(ReadPosition(), ReadPosition() + len, (char *)buf);
    }
    void ReadAndPop(void *buf, uint64_t len)
    {
        Read(buf, len);
        MoveReadOffset(len);
    }
    std::string ReadAsString(uint64_t len)
    {
        // 要求要获取的数据大小必须小于可读数据大小
        assert(len <= ReadAbleSize());
        std::string str;
        str.resize(len);
        Read(&str[0], len);
        return str;
    }
    std::string ReadAsStringAndPop(uint64_t len)
    {
        assert(len <= ReadAbleSize());
        std::string str = ReadAsString(len);
        MoveReadOffset(len);
        return str;
    }
    char *FindCRLF()
    {
        char *res = (char *)memchr(ReadPosition(), '\n', ReadAbleSize());
        return res;
    }
    /*通常获取一行数据，这种情况针对是*/
    std::string GetLine()
    {
        char *pos = FindCRLF();
        if (pos == NULL)
        {
            return "";
        }
        // +1是为了把换行字符也取出来。
        return ReadAsString(pos - ReadPosition() + 1);
    }
    std::string GetLineAndPop()
    {
        std::string str = GetLine();
        MoveReadOffset(str.size());
        return str;
    }
    // 清空缓冲区
    void Clear()
    {
        // 只需要将偏移量归0即可
        _reader_idx = 0;
        _writer_idx = 0;
    }
};

#define MAX_LISTEN 1024
class Socket
{
private:
    int _sockfd;

public:
    Socket() : _sockfd(-1) {}
    Socket(int fd) : _sockfd(fd) {}
    ~Socket() { Close(); }
    int Fd() { return _sockfd; }
    // 创建套接字
    bool Create()
    {
        // int socket(int domain, int type, int protocol)
        _sockfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
        if (_sockfd < 0)
        {
            ERR_LOG("CREATE SOCKET FAILED!!");
            return false;
        }
        return true;
    }
    // 绑定地址信息
    bool Bind(const std::string &ip, uint16_t port)
    {
        struct sockaddr_in addr;
        addr.sin_family = AF_INET;
        addr.sin_port = htons(port);
        addr.sin_addr.s_addr = inet_addr(ip.c_str());
        socklen_t len = sizeof(struct sockaddr_in);
        // int bind(int sockfd, struct sockaddr*addr, socklen_t len);
        int ret = bind(_sockfd, (struct sockaddr *)&addr, len);
        if (ret < 0)
        {
            ERR_LOG("BIND ADDRESS FAILED!");
            return false;
        }
        return true;
    }
    // 开始监听
    bool Listen(int backlog = MAX_LISTEN)
    {
        // int listen(int backlog)
        int ret = listen(_sockfd, backlog);
        if (ret < 0)
        {
            ERR_LOG("SOCKET LISTEN FAILED!");
            return false;
        }
        return true;
    }
    // 向服务器发起连接
    bool Connect(const std::string &ip, uint16_t port)
    {
        struct sockaddr_in addr;
        addr.sin_family = AF_INET;
        addr.sin_port = htons(port);
        addr.sin_addr.s_addr = inet_addr(ip.c_str());
        socklen_t len = sizeof(struct sockaddr_in);
        // int connect(int sockfd, struct sockaddr*addr, socklen_t len);
        int ret = connect(_sockfd, (struct sockaddr *)&addr, len);
        if (ret < 0)
        {
            ERR_LOG("CONNECT SERVER FAILED!");
            return false;
        }
        return true;
    }
    // 获取新连接
    int Accept()
    {
        // int accept(int sockfd, struct sockaddr *addr, socklen_t *len);
        int newfd = accept(_sockfd, NULL, NULL);
        if (newfd < 0)
        {
            ERR_LOG("SOCKET ACCEPT FAILED!");
            return -1;
        }
        return newfd;
    }
    // 接收数据
    ssize_t Recv(void *buf, size_t len, int flag = 0)
    {
        // ssize_t recv(int sockfd, void *buf, size_t len, int flag);
        ssize_t ret = recv(_sockfd, buf, len, flag);
        if (ret <= 0)
        {
            // EAGAIN 当前socket的接收缓冲区中没有数据了，在非阻塞的情况下才会有这个错误
            // EINTR  表示当前socket的阻塞等待，被信号打断了，
            if (errno == EAGAIN || errno == EINTR)
            {
                return 0; // 表示这次接收没有接收到数据
            }
            ERR_LOG("SOCKET RECV FAILED!!");
            return -1;
        }
        return ret; // 实际接收的数据长度
    }
    ssize_t NonBlockRecv(void *buf, size_t len)
    {
        return Recv(buf, len, MSG_DONTWAIT); // MSG_DONTWAIT 表示当前接收为非阻塞。
    }
    // 发送数据
    ssize_t Send(const void *buf, size_t len, int flag = 0)
    {
        // ssize_t send(int sockfd, void *data, size_t len, int flag);
        ssize_t ret = send(_sockfd, buf, len, flag);
        if (ret < 0)
        {
            if (errno == EAGAIN || errno == EINTR)
            {
                return 0;
            }
            ERR_LOG("SOCKET SEND FAILED!!");
            return -1;
        }
        return ret; // 实际发送的数据长度
    }
    ssize_t NonBlockSend(void *buf, size_t len)
    {
        if (len == 0)
            return 0;
        return Send(buf, len, MSG_DONTWAIT); // MSG_DONTWAIT 表示当前发送为非阻塞。
    }
    // 关闭套接字
    void Close()
    {
        if (_sockfd != -1)
        {
            close(_sockfd);
            _sockfd = -1;
        }
    }
    // 创建一个服务端连接
    bool CreateServer(uint16_t port, const std::string &ip = "0.0.0.0", bool block_flag = false)
    {
        // 1. 创建套接字，2. 绑定地址，3. 开始监听，4. 设置非阻塞， 5. 启动地址重用
        if (Create() == false)
            return false;
        if (block_flag)
            NonBlock();
        if (Bind(ip, port) == false)
            return false;
        if (Listen() == false)
            return false;
        ReuseAddress();
        return true;
    }
    // 创建一个客户端连接
    bool CreateClient(uint16_t port, const std::string &ip)
    {
        // 1. 创建套接字，2.指向连接服务器
        if (Create() == false)
            return false;
        if (Connect(ip, port) == false)
            return false;
        return true;
    }
    // 设置套接字选项---开启地址端口重用
    void ReuseAddress()
    {
        // int setsockopt(int fd, int leve, int optname, void *val, int vallen)
        int val = 1;
        setsockopt(_sockfd, SOL_SOCKET, SO_REUSEADDR, (void *)&val, sizeof(int));
        val = 1;
        setsockopt(_sockfd, SOL_SOCKET, SO_REUSEPORT, (void *)&val, sizeof(int));
    }
    // 设置套接字阻塞属性-- 设置为非阻塞
    void NonBlock()
    {
        // int fcntl(int fd, int cmd, ... /* arg */ );
        int flag = fcntl(_sockfd, F_GETFL, 0);
        fcntl(_sockfd, F_SETFL, flag | O_NONBLOCK);
    }
};

class Poller;
class EventLoop;
class Channel
{
private:
    int _fd;
    EventLoop *_loop;
    uint32_t _events;  // 当前需要监控的事件
    uint32_t _revents; // 当前连接触发的事件
    using EventCallback = std::function<void()>;
    EventCallback _read_callback;  // 可读事件被触发的回调函数
    EventCallback _write_callback; // 可写事件被触发的回调函数
    EventCallback _error_callback; // 错误事件被触发的回调函数
    EventCallback _close_callback; // 连接断开事件被触发的回调函数
    EventCallback _event_callback; // 任意事件被触发的回调函数
public:
    Channel(EventLoop *loop, int fd) : _fd(fd), _events(0), _revents(0), _loop(loop) {}
    int Fd() { return _fd; }
    uint32_t Events() { return _events; }                   // 获取想要监控的事件
    void SetREvents(uint32_t events) { _revents = events; } // 设置实际就绪的事件
    void SetReadCallback(const EventCallback &cb) { _read_callback = cb; }
    void SetWriteCallback(const EventCallback &cb) { _write_callback = cb; }
    void SetErrorCallback(const EventCallback &cb) { _error_callback = cb; }
    void SetCloseCallback(const EventCallback &cb) { _close_callback = cb; }
    void SetEventCallback(const EventCallback &cb) { _event_callback = cb; }
    // 当前是否监控了可读
    bool ReadAble() { return (_events & EPOLLIN); }
    // 当前是否监控了可写
    bool WriteAble() { return (_events & EPOLLOUT); }
    // 启动读事件监控
    void EnableRead()
    {
        _events |= EPOLLIN;
        Update();
    }
    // 启动写事件监控
    void EnableWrite()
    {
        _events |= EPOLLOUT;
        Update();
    }
    // 关闭读事件监控
    void DisableRead()
    {
        _events &= ~EPOLLIN;
        Update();
    }
    // 关闭写事件监控
    void DisableWrite()
    {
        _events &= ~EPOLLOUT;
        Update();
    }
    // 关闭所有事件监控
    void DisableAll()
    {
        _events = 0;
        Update();
    }
    // 移除监控
    void Remove();
    void Update();
    // 事件处理，一旦连接触发了事件，就调用这个函数，自己触发了什么事件如何处理自己决定
    void HandleEvent()
    {
        if ((_revents & EPOLLIN) || (_revents & EPOLLRDHUP) || (_revents & EPOLLPRI))
        {
            /*不管任何事件，都调用的回调函数*/
            if (_read_callback)
                _read_callback();
        }
        /*有可能会释放连接的操作事件，一次只处理一个*/
        if (_revents & EPOLLOUT)
        {
            if (_write_callback)
                _write_callback();
        }
        else if (_revents & EPOLLERR)
        {
            if (_error_callback)
                _error_callback(); // 一旦出错，就会释放连接，因此要放到前边调用任意回调
        }
        else if (_revents & EPOLLHUP)
        {
            if (_close_callback)
                _close_callback();
        }
        if (_event_callback)
            _event_callback();
    }
};
#define MAX_EPOLLEVENTS 1024
class Poller
{
private:
    int _epfd;
    struct epoll_event _evs[MAX_EPOLLEVENTS];
    std::unordered_map<int, Channel *> _channels;

private:
    // 对epoll的直接操作
    void Update(Channel *channel, int op)
    {
        // int epoll_ctl(int epfd, int op,  int fd,  struct epoll_event *ev);
        int fd = channel->Fd();
        struct epoll_event ev;
        ev.data.fd = fd;
        ev.events = channel->Events();
        int ret = epoll_ctl(_epfd, op, fd, &ev);
        if (ret < 0)
        {
            ERR_LOG("EPOLLCTL FAILED!");
        }
        return;
    }
    // 判断一个Channel是否已经添加了事件监控
    bool HasChannel(Channel *channel)
    {
        auto it = _channels.find(channel->Fd());
        if (it == _channels.end())
        {
            return false;
        }
        return true;
    }

public:
    Poller()
    {
        _epfd = epoll_create(MAX_EPOLLEVENTS);
        if (_epfd < 0)
        {
            ERR_LOG("EPOLL CREATE FAILED!!");
            abort(); // 退出程序
        }
    }
    // 添加或修改监控事件
    void UpdateEvent(Channel *channel)
    {
        bool ret = HasChannel(channel);
        if (ret == false)
        {
            // 不存在则添加
            _channels.insert(std::make_pair(channel->Fd(), channel));
            return Update(channel, EPOLL_CTL_ADD);
        }
        return Update(channel, EPOLL_CTL_MOD);
    }
    // 移除监控
    void RemoveEvent(Channel *channel)
    {
        auto it = _channels.find(channel->Fd());
        if (it != _channels.end())
        {
            _channels.erase(it);
        }
        Update(channel, EPOLL_CTL_DEL);
    }
    // 开始监控，返回活跃连接
    void Poll(std::vector<Channel *> *active)
    {
        // int epoll_wait(int epfd, struct epoll_event *evs, int maxevents, int timeout)
        int nfds = epoll_wait(_epfd, _evs, MAX_EPOLLEVENTS, -1);
        if (nfds < 0)
        {
            if (errno == EINTR)
            {
                return;
            }
            ERR_LOG("EPOLL WAIT ERROR:%s\n", strerror(errno));
            abort(); // 退出程序
        }
        for (int i = 0; i < nfds; i++)
        {
            auto it = _channels.find(_evs[i].data.fd);
            assert(it != _channels.end());
            it->second->SetREvents(_evs[i].events); // 设置实际就绪的事件
            active->push_back(it->second);
        }
        return;
    }
};

using TaskFunc = std::function<void()>;
using ReleaseFunc = std::function<void()>;
class TimerTask
{
private:
    uint64_t _id;         // 定时器任务对象ID
    uint32_t _timeout;    // 定时任务的超时时间
    bool _canceled;       // false-表示没有被取消， true-表示被取消
    TaskFunc _task_cb;    // 定时器对象要执行的定时任务
    ReleaseFunc _release; // 用于删除TimerWheel中保存的定时器对象信息
public:
    TimerTask(uint64_t id, uint32_t delay, const TaskFunc &cb) : _id(id), _timeout(delay), _task_cb(cb), _canceled(false) {}
    ~TimerTask()
    {
        if (_canceled == false)
            _task_cb();
        _release();
    }
    void Cancel() { _canceled = true; }
    void SetRelease(const ReleaseFunc &cb) { _release = cb; }
    uint32_t DelayTime() { return _timeout; }
};

class TimerWheel
{
private:
    using WeakTask = std::weak_ptr<TimerTask>;
    using PtrTask = std::shared_ptr<TimerTask>;
    int _tick;     // 当前的秒针，走到哪里释放哪里，释放哪里，就相当于执行哪里的任务
    int _capacity; // 表盘最大数量---其实就是最大延迟时间
    std::vector<std::vector<PtrTask>> _wheel;
    std::unordered_map<uint64_t, WeakTask> _timers;

    EventLoop *_loop;
    int _timerfd; // 定时器描述符--可读事件回调就是读取计数器，执行定时任务
    std::unique_ptr<Channel> _timer_channel;

private:
    void RemoveTimer(uint64_t id)
    {
        auto it = _timers.find(id);
        if (it != _timers.end())
        {
            _timers.erase(it);
        }
    }
    static int CreateTimerfd()
    {
        int timerfd = timerfd_create(CLOCK_MONOTONIC, 0);
        if (timerfd < 0)
        {
            ERR_LOG("TIMERFD CREATE FAILED!");
            abort();
        }
        // int timerfd_settime(int fd, int flags, struct itimerspec *new, struct itimerspec *old);
        struct itimerspec itime;
        itime.it_value.tv_sec = 1;
        itime.it_value.tv_nsec = 0; // 第一次超时时间为1s后
        itime.it_interval.tv_sec = 1;
        itime.it_interval.tv_nsec = 0; // 第一次超时后，每次超时的间隔时
        timerfd_settime(timerfd, 0, &itime, NULL);
        return timerfd;
    }
    int ReadTimefd()
    {
        uint64_t times;
        // 有可能因为其他描述符的事件处理花费事件比较长，然后在处理定时器描述符事件的时候，有可能就已经超时了很多次
        // read读取到的数据times就是从上一次read之后超时的次数
        int ret = read(_timerfd, &times, 8);
        if (ret < 0)
        {
            ERR_LOG("READ TIMEFD FAILED!");
            abort();
        }
        return times;
    }
    // 这个函数应该每秒钟被执行一次，相当于秒针向后走了一步
    void RunTimerTask()
    {
        _tick = (_tick + 1) % _capacity;
        _wheel[_tick].clear(); // 清空指定位置的数组，就会把数组中保存的所有管理定时器对象的shared_ptr释放掉
    }
    void OnTime()
    {
        // 根据实际超时的次数，执行对应的超时任务
        int times = ReadTimefd();
        for (int i = 0; i < times; i++)
        {
            RunTimerTask();
        }
    }
    void TimerAddInLoop(uint64_t id, uint32_t delay, const TaskFunc &cb)
    {
        PtrTask pt(new TimerTask(id, delay, cb));
        pt->SetRelease(std::bind(&TimerWheel::RemoveTimer, this, id));
        int pos = (_tick + delay) % _capacity;
        _wheel[pos].push_back(pt);
        _timers[id] = WeakTask(pt);
    }
    void TimerRefreshInLoop(uint64_t id)
    {
        // 通过保存的定时器对象的weak_ptr构造一个shared_ptr出来，添加到轮子中
        auto it = _timers.find(id);
        if (it == _timers.end())
        {
            return; // 没找着定时任务，没法刷新，没法延迟
        }
        PtrTask pt = it->second.lock(); // lock获取weak_ptr管理的对象对应的shared_ptr
        int delay = pt->DelayTime();
        int pos = (_tick + delay) % _capacity;
        _wheel[pos].push_back(pt);
    }
    void TimerCancelInLoop(uint64_t id)
    {
        auto it = _timers.find(id);
        if (it == _timers.end())
        {
            return; // 没找着定时任务，没法刷新，没法延迟
        }
        PtrTask pt = it->second.lock();
        if (pt)
            pt->Cancel();
    }

public:
    TimerWheel(EventLoop *loop) : _capacity(60), _tick(0), _wheel(_capacity), _loop(loop),
                                  _timerfd(CreateTimerfd()), _timer_channel(new Channel(_loop, _timerfd))
    {
        _timer_channel->SetReadCallback(std::bind(&TimerWheel::OnTime, this));
        _timer_channel->EnableRead(); // 启动读事件监控
    }
    /*定时器中有个_timers成员，定时器信息的操作有可能在多线程中进行，因此需要考虑线程安全问题*/
    /*如果不想加锁，那就把对定期的所有操作，都放到一个线程中进行*/
    void TimerAdd(uint64_t id, uint32_t delay, const TaskFunc &cb);
    // 刷新/延迟定时任务
    void TimerRefresh(uint64_t id);
    void TimerCancel(uint64_t id);
    /*这个接口存在线程安全问题--这个接口实际上不能被外界使用者调用，只能在模块内，在对应的EventLoop线程内执行*/
    bool HasTimer(uint64_t id)
    {
        auto it = _timers.find(id);
        if (it == _timers.end())
        {
            return false;
        }
        return true;
    }
};

class EventLoop
{
private:
    using Functor = std::function<void()>;
    std::thread::id _thread_id; // 线程ID
    int _event_fd;              // eventfd唤醒IO事件监控有可能导致的阻塞
    std::unique_ptr<Channel> _event_channel;
    Poller _poller;              // 进行所有描述符的事件监控
    std::vector<Functor> _tasks; // 任务池
    std::mutex _mutex;           // 实现任务池操作的线程安全
    TimerWheel _timer_wheel;     // 定时器模块
public:
    // 执行任务池中的所有任务
    void RunAllTask()
    {
        std::vector<Functor> functor;
        {
            std::unique_lock<std::mutex> _lock(_mutex);
            _tasks.swap(functor);
        }
        for (auto &f : functor)
        {
            f();
        }
        return;
    }
    static int CreateEventFd()
    {
        int efd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
        if (efd < 0)
        {
            ERR_LOG("CREATE EVENTFD FAILED!!");
            abort(); // 让程序异常退出
        }
        return efd;
    }
    void ReadEventfd()
    {
        uint64_t res = 0;
        int ret = read(_event_fd, &res, sizeof(res));
        if (ret < 0)
        {
            // EINTR -- 被信号打断；   EAGAIN -- 表示无数据可读
            if (errno == EINTR || errno == EAGAIN)
            {
                return;
            }
            ERR_LOG("READ EVENTFD FAILED!");
            abort();
        }
        return;
    }
    void WeakUpEventFd()
    {
        uint64_t val = 1;
        int ret = write(_event_fd, &val, sizeof(val));
        if (ret < 0)
        {
            if (errno == EINTR)
            {
                return;
            }
            ERR_LOG("READ EVENTFD FAILED!");
            abort();
        }
        return;
    }

public:
    EventLoop() : _thread_id(std::this_thread::get_id()),
                  _event_fd(CreateEventFd()),
                  _event_channel(new Channel(this, _event_fd)),
                  _timer_wheel(this)
    {
        // 给eventfd添加可读事件回调函数，读取eventfd事件通知次数
        _event_channel->SetReadCallback(std::bind(&EventLoop::ReadEventfd, this));
        // 启动eventfd的读事件监控
        _event_channel->EnableRead();
    }
    // 三步走--事件监控-》就绪事件处理-》执行任务
    void Start()
    {
        while (1)
        {
            // 1. 事件监控，
            std::vector<Channel *> actives;
            _poller.Poll(&actives);
            // 2. 事件处理。
            for (auto &channel : actives)
            {
                channel->HandleEvent();
            }
            // 3. 执行任务
            RunAllTask();
        }
    }
    // 用于判断当前线程是否是EventLoop对应的线程；
    bool IsInLoop()
    {
        return (_thread_id == std::this_thread::get_id());
    }
    void AssertInLoop()
    {
        assert(_thread_id == std::this_thread::get_id());
    }
    // 判断将要执行的任务是否处于当前线程中，如果是则执行，不是则压入队列。
    void RunInLoop(const Functor &cb)
    {
        if (IsInLoop())
        {
            return cb();
        }
        return QueueInLoop(cb);
    }
    // 将操作压入任务池
    void QueueInLoop(const Functor &cb)
    {
        {
            std::unique_lock<std::mutex> _lock(_mutex);
            _tasks.push_back(cb);
        }
        // 唤醒有可能因为没有事件就绪，而导致的epoll阻塞；
        // 其实就是给eventfd写入一个数据，eventfd就会触发可读事件
        WeakUpEventFd();
    }
    // 添加/修改描述符的事件监控
    void UpdateEvent(Channel *channel) { return _poller.UpdateEvent(channel); }
    // 移除描述符的监控
    void RemoveEvent(Channel *channel) { return _poller.RemoveEvent(channel); }
    void TimerAdd(uint64_t id, uint32_t delay, const TaskFunc &cb) { return _timer_wheel.TimerAdd(id, delay, cb); }
    void TimerRefresh(uint64_t id) { return _timer_wheel.TimerRefresh(id); }
    void TimerCancel(uint64_t id) { return _timer_wheel.TimerCancel(id); }
    bool HasTimer(uint64_t id) { return _timer_wheel.HasTimer(id); }
};

class LoopThread
{
private:
    std::mutex _mutex;
    std::condition_variable _cond;
    EventLoop *_loop;
    std::thread _thread;

private:
    void ThreadEntry()
    {
        EventLoop loop;
        {
            std::unique_lock<std::mutex> lock(_mutex);
            _loop = &loop;
            _cond.notify_all();
        }
        loop.Start();
    }

public:
    LoopThread() : _loop(nullptr), _thread(std::thread(&LoopThread::ThreadEntry, this)) {}
    EventLoop *GetLoop()
    {
        EventLoop *loop = nullptr;
        {
            std::unique_lock<std::mutex> lock(_mutex);
            _cond.wait(lock, [&]()
                       { return _loop != nullptr; });
            loop = _loop;
            return loop;
        }
    }
};

class LoopThreadPool
{
private:
    int _thread_count;
    int _next_idx;
    EventLoop *_baseloop;
    std::vector<LoopThread *> _threads;
    std::vector<EventLoop *> _loops;

public:
    LoopThreadPool(EventLoop *baseloop) : _thread_count(0), _next_idx(0), _baseloop(baseloop) {}
    void SetThreadCount(int count)
    {
        _thread_count = count;
    }
    void Create()
    {
        if (_thread_count > 0)
        {
            _threads.resize(_thread_count);
            _loops.resize(_thread_count);
            for (int i = 0; i < _thread_count; i++)
            {
                _threads[i] = new LoopThread();
                _loops[i] = _threads[i]->GetLoop();
            }
        }
        return;
    }
    EventLoop *NextLoop()
    {
        if (_thread_count == 0)
        {
            return _baseloop;
        }
        _next_idx = (_next_idx + 1) % _thread_count;
        return _loops[_next_idx];
    }
};

class Any
{
private:
    /*父类holder，用到多态*/
    class holder
    {
    public:
        ~holder() {}
        virtual holder *clone() = 0;
        virtual std::type_info type() = 0;
    };
    template <class T>
    class placeholder : holder
    {
    public:
        virtual holder *clone() override
        {
            return new placeholder(_val);
        }
        virtual std::type_info type() override
        {
            return typeid(T);
        }
        placeholder(const T &val) : _val(val) {}
        T &Getval()
        {
            return _val;
        }

    private:
        T _val;
    };
    holder *_content;
    Any &swap(Any &other)
    {
        std::swap(_content, other._content);
        return *this;
    }

public:
    Any() : _content(nullptr) {}
    template <class T>
    Any(const T &val) : _content(new placeholder<T>(val)) {}
    Any(const Any &other) : _content(other._content == nullptr ? nullptr : other._content->clone()) {}
    ~Any() { delete _content; }
    template <class T>
    T *get()
    {
        assert(_content->type() == typeid(T));
        return &(((placeholder<T> *)_content)->Getval());
    }
    template <class T>
    Any &operator=(const T &val)
    {
        return Any(val).swap(*this);
    }
    Any &operator=(const Any &other)
    {
        return Any(other).swap(*this);
    }
};

class Connection;
typedef enum
{
    DISCONNECTED,
    CONNECTING,
    CONNECTED,
    DISCONNECTING
} ConnStatu;
using PtrConnection = std::shared_ptr<Connection>;
class Connection : public std::enable_shared_from_this<Connection>
{
private:
    uint64_t _conn_id;
    int _sockfd;
    bool _enable_inactive_release;
    EventLoop *_loop;
    ConnStatu _statu;
    Socket _socket;
    Channel _channel;
    Buffer _in_buffer;
    Buffer _out_buffer;
    Any _context;

    using ConnectedCallback = std::function<void(const PtrConnection &)>;
    using MessageCallback = std::function<void(const PtrConnection &, Buffer *)>;
    using ClosedCallback = std::function<void(const PtrConnection &)>;
    using AnyEventCallback = std::function<void(const PtrConnection &)>;

    ConnectedCallback _connected_callback;
    MessageCallback _message_callback;
    ClosedCallback _closed_callback;
    AnyEventCallback _event_callback;

    ClosedCallback _server_closed_callback;

private:
    void HandleRead()
    {
        char buf[65536];
        ssize_t ret = _socket.NonBlockRecv(buf, 65535);
        if (ret < 0)
        {
            return ShutdownInLoop();
        }
        _in_buffer.WriteAndPush(buf, ret);
        if (_in_buffer.ReadAbleSize() > 0)
        {
            return _message_callback(shared_from_this(), &_in_buffer);
        }
    }
    void HandleWrite()
    {
        ssize_t ret = _socket.NonBlockSend(_out_buffer.ReadPosition(), _out_buffer.ReadAbleSize());
        if (ret < 0)
        {
            if (_in_buffer.ReadAbleSize() > 0)
            {
                _message_callback(shared_from_this(), &_in_buffer);
            }
            return Release();
        }
        _out_buffer.MoveReadOffset(ret);
        if (_out_buffer.ReadAbleSize() == 0)
        {
            _channel.DisableWrite();
            if (_statu == DISCONNECTING)
            {
                return Release();
            }
        }
        return;
    }
    void HandleClose()
    {
        if (_in_buffer.ReadAbleSize() > 0)
        {
            _message_callback(shared_from_this(), &_in_buffer);
        }
        return Release();
    }
    void HandleError()
    {
        return HandleClose();
    }
    void HandleEvent()
    {
        if (_enable_inactive_release == true)
        {
            _loop->TimerRefresh(_conn_id);
        }
        if (_event_callback)
        {
            _event_callback(shared_from_this());
        }
    }
    void EstablishedInLoop()
    {
        assert(_statu == CONNECTING);
        _statu = CONNECTED;
        _channel.EnableRead();
        if (_connected_callback)
        {
            _connected_callback(shared_from_this());
        }
    }
    void ReleaseInLoop()
    {
        _statu = DISCONNECTED;
        _channel.Remove();
        _socket.Close();
        if (_loop->HasTimer(_conn_id))
        {
            CancelInactiveReleaseInLoop();
        }
        if (_closed_callback)
        {
            _closed_callback(shared_from_this());
        }
        if (_server_closed_callback)
        {
            _server_closed_callback(shared_from_this());
        }
    }
    void SendInLoop(Buffer &buf)
    {
        if (_statu == DISCONNECTED)
        {
            return;
        }
        _out_buffer.WriteBufferAndPush(buf);
        if (_channel.WriteAble() == false)
        {
            _channel.EnableWrite();
        }
    }
    void ShutdownInLoop()
    {
        _statu = DISCONNECTING;
        if (_in_buffer.ReadAbleSize() > 0)
        {
            if (_message_callback)
            {
                _message_callback(shared_from_this(), &_in_buffer);
            }
        }
        if (_out_buffer.ReadAbleSize() > 0)
        {
            if (_channel.WriteAble() == false)
            {
                _channel.EnableWrite();
            }
        }
        if (_out_buffer.ReadAbleSize() == 0)
        {
            Release();
        }
    }
    void EnableInactiveReleaseInLoop(int sec)
    {
        _enable_inactive_release = true;
        if (_loop->HasTimer(_conn_id))
        {
            return _loop->TimerRefresh(_conn_id);
        }
        _loop->TimerAdd(_conn_id, sec, std::bind(&Connection::Release, this));
    }
    void CancelInactiveReleaseInLoop()
    {
        _enable_inactive_release = false;
        if (_loop->HasTimer(_conn_id))
        {
            _loop->TimerCancel(_conn_id);
        }
    }
    void UpgradeInLoop(const Any &context, const ConnectedCallback &conn, const MessageCallback &msg, const ClosedCallback &closed, const AnyEventCallback &event)
    {
        _context = context;
        _connected_callback = conn;
        _message_callback = msg;
        _closed_callback = closed;
        _event_callback = event;
    }

public:
    Connection(EventLoop *loop, uint64_t conn_id, int sockfd) : _conn_id(conn_id), _sockfd(sockfd), _enable_inactive_release(false), _loop(loop), _statu(CONNECTING), _socket(_sockfd),
                                                                _channel(_loop, _sockfd)
    {
        _channel.SetCloseCallback(std::bind(&Connection::HandleClose, this));
        _channel.SetEventCallback(std::bind(&Connection::HandleEvent, this));
        _channel.SetReadCallback(std::bind(&Connection::HandleRead, this));
        _channel.SetWriteCallback(std::bind(&Connection::HandleWrite, this));
        _channel.SetErrorCallback(std::bind(&Connection::HandleError, this));
    }
    ~Connection()
    {
        std::cout << "RELEASE CONNECTION:" << this << std::endl;
    }
    int Fd()
    {
        return _sockfd;
    }
    int Id()
    {
        return _conn_id;
    }
    bool Connected()
    {
        return (_statu == CONNECTED);
    }
    void SetContext(const Any &context)
    {
        _context = context;
    }
    Any *GetContext()
    {
        return &_context;
    }
    void SetConnectedCallback(const ConnectedCallback &cb) { _connected_callback = cb; }
    void SetMessageCallback(const MessageCallback &cb) { _message_callback = cb; }
    void SetClosedCallback(const ClosedCallback &cb) { _closed_callback = cb; }
    void SetAnyEventCallback(const AnyEventCallback &cb) { _event_callback = cb; }
    void SetSrvClosedCallback(const ClosedCallback &cb) { _server_closed_callback = cb; }
    void Established()
    {
        _loop->RunInLoop(std::bind(&Connection::EstablishedInLoop, this));
    }
    void Send(const char *data, size_t len)
    {
        Buffer buf;
        buf.WriteAndPush(data, len);
        _loop->RunInLoop(std::bind(&Connection::SendInLoop, this, std::move(buf)));
    }
    void Shutdown()
    {
        _loop->RunInLoop(std::bind(&Connection::ShutdownInLoop, this));
    }
    void Release()
    {
        _loop->QueueInLoop(std::bind(&Connection::ReleaseInLoop, this));
    }
    void EnableInactiveRelease(int sec)
    {
        _loop->RunInLoop(std::bind(&Connection::EnableInactiveReleaseInLoop, this, sec));
    }
    void CancelInactiveRelease()
    {
        _loop->RunInLoop(std::bind(&Connection::CancelInactiveReleaseInLoop, this));
    }
    void Upgrade(const Any &context, const ConnectedCallback &conn, const MessageCallback &msg,
                 const ClosedCallback &closed, const AnyEventCallback &event)
    {
        _loop->AssertInLoop();
        _loop->RunInLoop(std::bind(&Connection::UpgradeInLoop, this, context, conn, msg, closed, event));
    }
};

class Acceptor
{
private:
    Socket _socket;
    EventLoop *_loop;
    Channel _channel;

    using AcceptCallback = std::function<void(int)>;
    AcceptCallback _accept_callback;

private:
    void HandleRead()
    {
        int newfd = _socket.Accept();
        if (newfd < 0)
        {
            return;
        }
        if (_accept_callback)
        {
            _accept_callback(newfd);
        }
    }
    int CreateServer(int port)
    {
        bool ret = _socket.CreateServer(port);
        assert(ret == true);
        return _socket.Fd();
    }

public:
    Acceptor(EventLoop *loop, int port) : _socket(CreateServer(port)), _loop(loop), _channel(loop, _socket.Fd())
    {
        _channel.SetReadCallback(std::bind(&Acceptor::HandleRead, this));
    }
    void SetAcceptCallback(const AcceptCallback &cb)
    {
        _accept_callback = cb;
    }
    void Listen()
    {
        _channel.EnableRead();
    }
};

class TcpServer
{
private:
    uint64_t _next_id;
    int _port;
    int _timeout;
    bool _enable_inactive_release;
    EventLoop _baseloop;
    Acceptor _acceptor;
    LoopThreadPool _pool;
    std::unordered_map<uint64_t, PtrConnection> _conns;

    using ConnectedCallback = std::function<void(const PtrConnection &)>;
    using MessageCallback = std::function<void(const PtrConnection &, Buffer *)>;
    using ClosedCallback = std::function<void(const PtrConnection &)>;
    using AnyEventCallback = std::function<void(const PtrConnection &)>;
    using Functor = std::function<void()>;
    ConnectedCallback _connected_callback;
    MessageCallback _message_callback;
    ClosedCallback _closed_callback;
    AnyEventCallback _event_callback;

private:
    void RunAfterInLoop(const Functor &task, int delay)
    {
        _next_id++;
        _baseloop.TimerAdd(_next_id, delay, task);
    }
    void NewConnection(int fd)
    {
        _next_id++;
        PtrConnection conn(new Connection(_pool.NextLoop(), _next_id, fd));
        conn->SetMessageCallback(_message_callback);
        conn->SetClosedCallback(_closed_callback);
        conn->SetConnectedCallback(_connected_callback);
        conn->SetAnyEventCallback(_event_callback);
        conn->SetSrvClosedCallback(std::bind(&TcpServer::RemoveConnection, this, std::placeholders::_1));
        if (_enable_inactive_release)
        {
            conn->EnableInactiveRelease(_timeout);
        }
        conn->Established();
        _conns.insert(std::make_pair(_next_id, conn));
    }
    void RemoveConnectionInLoop(const PtrConnection &conn)
    {
        int id = conn->Id();
        auto it = _conns.find(id);
        if (it != _conns.end())
        {
            _conns.erase(it);
        }
    }

public:
    TcpServer(int port) : _port(port),
                          _next_id(0),
                          _enable_inactive_release(false),
                          _acceptor(&_baseloop, port),
                          _pool(&_baseloop)
    {
        _acceptor.SetAcceptCallback(std::bind(&TcpServer::NewConnection, this, std::placeholders::_1));
        _acceptor.Listen(); // 将监听套接字挂到baseloop上
    }
    void RemoveConnection(const PtrConnection &conn)
    {
        _baseloop.RunInLoop(std::bind(&TcpServer::RemoveConnectionInLoop, this, conn));
    }
    void SetThreadCount(int count) { return _pool.SetThreadCount(count); }
    void SetConnectedCallback(const ConnectedCallback &cb) { _connected_callback = cb; }
    void SetMessageCallback(const MessageCallback &cb) { _message_callback = cb; }
    void SetClosedCallback(const ClosedCallback &cb) { _closed_callback = cb; }
    void SetAnyEventCallback(const AnyEventCallback &cb) { _event_callback = cb; }
    void EnableInactiveRelease(int timeout)
    {
        _timeout = timeout;
        _enable_inactive_release = true;
    }
    // 用于添加一个定时任务
    void RunAfter(const Functor &task, int delay)
    {
        _baseloop.RunInLoop(std::bind(&TcpServer::RunAfterInLoop, this, task, delay));
    }
    void Start()
    {
        _pool.Create();
        _baseloop.Start();
    }
};

void Channel::Remove() { return _loop->RemoveEvent(this); }
void Channel::Update() { return _loop->UpdateEvent(this); }
void TimerWheel::TimerAdd(uint64_t id, uint32_t delay, const TaskFunc &cb)
{
    _loop->RunInLoop(std::bind(&TimerWheel::TimerAddInLoop, this, id, delay, cb));
}
// 刷新/延迟定时任务
void TimerWheel::TimerRefresh(uint64_t id)
{
    _loop->RunInLoop(std::bind(&TimerWheel::TimerRefreshInLoop, this, id));
}
void TimerWheel::TimerCancel(uint64_t id)
{
    _loop->RunInLoop(std::bind(&TimerWheel::TimerCancelInLoop, this, id));
}
